The present invention relates to combustion engines. Specifically, the present invention relates to non-fixed compression ratio, compression ignition, two-stroke, rotating/reciprocating, internal combustion engines that convert combustion energy into direct hydraulic work.
Conventional internal combustion engines use two different processes, constant volume and constant pressure. The constant volume process is characteristic of spark-ignition engines or the Otto cycle. A spark ignition engine uses volatile liquid fuels such as gasoline, compression ratios from 6:1 to 12:1, and compression pressures from 1034 to 2068 kPa. Engine load and speed are controlled by throttling the fuel charge. The constant pressure process is typified by diesel engines or compression ignition engines. A compression ignition engine uses low volatility liquid fuels from fuel oil to crude oil, compression ratios from 11.5:1 to 22:1, and compression pressures from 2768 to 4830 kPa. Engine load and speed are controlled by varying the fuel quantity injected.
Three general types of arrangements of engines are used, four stroke, two stroke, and rotary or Wankel engines. These engines are typically fixed piston engines. That is, the pistons have a predetermined and constant or fixed stroke. This stroke is set up for the particular type of fuel to be used in the engine. Moreover, the pistons are connected through a connecting rod to a crankshaft in order to convert the combustion energy into mechanical work. The crankshaft in turn is used to drive all of the other systems of the automobile or machine. So, the nature of these engines is to produce net mechanical shaft work.
Numerous innovations for combustion engines have been attempted to improve the efficiency, and hence output or work, of an engine without adding undue cost or size. Engines exist that combine the rotation of a rotary engine with the reciprocation of pistons. For example, U.S. Pat. No. 3,990,406 discloses a roto-reciprocating engine arranged to provide an engine that has a large cubic inch displacement per pound of unit weight and therefore a good horsepower to weight ratio. The engine includes a chamber, a piston in the chamber mounted on a crankshaft, and an orientation member arranged to make it possible for the piston to orbit around the crankshaft center while remaining in a substantially oriented position.
U.S. Pat. No. 5,433,176 discloses a rotary-reciprocal combustion engine. The engine includes a rotor which has circular pistons on the lateral peripheral area of the rotor and which is reciprocatively mounted on a rotor with a shaft centrally located in a fixed housing having a cavity formed by a circular peripheral wall and two sidewalls. The circular pistons or sealing mechanisms or apparatus reciprocate on the peripheral area of the rotor while rotating with the rotor and shaft. U.S. Pat. No. 5,070,825 discloses a rotary engine with a wobble plate and a plurality of pistons reciprocating within cylinders.
U.S. Pat. No. 4,166,438 is directed to a machine with reciprocating pistons and a rotating piston carrier. The engine overcomes sealing deficiencies of rotary engines by using conventional pistons. The engine includes a housing surrounding a workshaft, a carrier in the housing about the shaft and rotatable about the shaft axis, a plurality of continuous walls within the carrier each defining a chamber, and a piston in each chamber connected to a crankshaft where each crankshaft is linked to the housing to induce relative movement between the housing and the carrier. Induced motion of the pistons results in a revolution of throw arms of the cranks, causing motion of the gears with respect to the timing gear, thus imposing rotational motion on the carrier and shaft.
Other engines use a free piston arrangement, wherein the stroke of the piston is not set by attachment to a shaft of predetermined length. U.S. Pat. Nos. 4,399,654, 4,561,252, and 4,702,205 disclose such engines. Further, in these engines, the combusted gas exhaust is used to turn vanes in a motor to produce shaft power. U.S. Pat. No. 3,989,011 discloses a constant pressure heating vane engine. This engine uses a system similar to a gas turbine to generate shaft work.
U.S. Pat. No. 5,327,857 discloses a vehicle using a crankless, unthrottled internal combustion engine directly powering its wheels hydrostatically. The vehicle uses a spark or compression ignited two-cycle type engine, an optional recovery and reuse of a portion of its braking energy, and hydraulic pressure for compression of the air and fuel mixture. U.S. Pat. No. 4,382,748 discloses an opposed piston type free piston engine pump for converting combustion energy into hydraulic power. The motion of the engine is at least substantially directly delivered to hydraulic pumping elements, usually, without crankshaft and connecting rod arrangements of conventional rotary engines. The engine includes a pump piston and engine pistons arranged for linear in-line reciprocation wherein the hydraulic pump portion supplies energy for effecting a compression stroke to bring the engine pistons toward one another thereby to effect compression.
In accordance with the present invention a reciprocating rotating internal combustion engine is provided having a more direct conversion of combustible gases into hydraulic pressure. The reciprocating rotating engine utilizes a non-fixed compression ratio free piston having a compression ignited two-stroke reciprocating and rotating cycle. This arrangement permits multi-fuel use.
The reciprotating rotating internal combustion engine for producing direct hydraulic work includes a combustion assembly housing, a combustion chamber disposed within the combustion housing, at least one free piston disposed within the combustion chamber and dividing the combustion chamber into at least a first combustion chamber portion and a second combustion chamber portion, the free piston moveable between a first piston position and a second piston position, a pumping assembly housing, a pumping chamber disposed within the pumping housing, and at least one pump vane disposed within the pumping chamber and dividing the pumping chamber into at least a first pumping chamber and a second pumping chamber, the pump vane coupled to the free piston so as to be moveable therewith between a first pump position and a second pump position corresponding to the first and second piston positions respectively. The free piston reciprocates between the first and second piston positions under a combustion event force in either one of the first or second combustion chambers to compress combustion gases in the other one of the first or second combustion chambers and to move the pump vane between the first and second pump vane positions to drive a working fluid through the pumping chamber.
In one embodiment, the at least one piston and the at least one pump vane in moving between their respective first and second positions follow concentric circular paths. In another embodiment, the circular pump vane path is nested within the circular piston path and the at least one piston and the at least on pump vane are arranged about a common axis. Preferably, the combustion event is caused by compression ignition of fuel gases disposed within the combustion chamber.
The engine further includes at least one exhaust port per combustion chamber portion for passively exhausting combustion gases. The engine also includes at least one combustion chamber injection port per combustion chamber portion for injecting fuel gases into the combustion chamber portions. In one embodiment, the at least one pump vane in reciprocating between the first and second pump positions simultaneously fills one of the pumping chamber portions with the working fluid and pressurizes the working fluid in the other pumping chamber portion. In another embodiment, the engine includes a plurality of check valves to direct the flow of the working fluid through the pumping chamber.
In one embodiment, the engine includes at least two pairs of pistons arranged to define at least four combustion chamber portions, and at least two pairs of pump vanes arranged to define at least four pumping chamber portions. In another embodiment, the combustion housing is cylindrical and has an outer housing radius, the at least four combustion chamber portions are disposed in a first ring concentric with the combustion housing, and the at least four pump chambers are disposed in a second ring concentric with the housing. In yet another embodiment, the first ring is disposed within the outer housing radius and the second ring is disposed within the first ring.
In one embodiment, each pair of pistons are attached to one pair of pump vanes to form combined piston and pump vane pairs, the combined pairs are collinear and transverse to the axis of common rotation and are rotatable with respect thereto, and the at least four combustion chamber portions and pumping chamber portions are disposed around the circle between adjacent pistons and pump vanes respectively.
The engine further includes at least two rotors, each rotor includes one of the combined pairs and a portion of the pumping housing such that when all of the rotors are combined, a complete pumping chamber is formed. In one embodiment, the pairs of pistons reciprocally rotate with respect to one another so as to sequentially compress and expand the combustion chamber portions in pairs disposed on either side of each piston, and the pump vanes reciprocally rotate with respect to one another so as to sequentially intake and pressurize the working fluid in pump chamber portions disposed on either side of each pump vane. In another embodiment, each pump vane includes at least one check valve such that as the pump vanes rotate the check valve directs hydraulic fluid either alternatively into pumping chamber portions disposed on either side of each pump vane or out of pumping chambers portions disposed on either side of each pump vane. In yet another embodiment, each piston reciprocally rotates within the combustion chamber through an angle of up to about 70xc2x0.
In one embodiment, the engine further includes one exhaust port per combustion chamber portion and one combustion chamber injection port per combustion chamber portion, wherein the exhaust ports are equally spaced around the combustion chamber at an angular separation of up to about 90xc2x0, each injection port is equally spaced around the combustion chamber at an angular separation of up to about 90xc2x0, and the exhaust and injection or intake ports are equally spaced from one another by an angle of up to about 45xc2x0. In another embodiment, each injection port includes a valve, at least one of the combined pairs is connected to a sequencing shaft, and the sequencing shaft and the valves are operatively connected so as to synchronize the rotation of the pistons and the opening and closing of the injection valves. In yet another embodiment, each cycle of the engine comprises two strokes and at least four power strokes. In still yet another embodiment, the engine includes a starter mechanism coupled to the at least one free piston and capable of moving the free piston between the first and second pistons positions so as to initiate a self-sustaining engine cycle.
The present invention is also directed to an engine for producing direct hydraulic work having a housing having at least one combustion chamber disposed with the housing, at least one piston disposed within the combustion chamber and dividing the combustion chamber into at least a first combustion chamber portion and a second combustion chamber portion, the piston moveable between a first piston position and a second piston position, at least one fuel intake port disposed in the housing to allow passage of fuel into the first and second combustion chamber portions, a pumping chamber disposed within the housing, and at least one pump vane disposed within the pumping chamber and dividing the pumping chamber into at least a first pumping chamber portion and a second pumping chamber portion, the pump vane coupled to the piston so as to be moveable therewith between a first pump position and a second pump position corresponding to the first and second piston positions respectively. The piston is dimensioned and configured so as to reciprocate between the first and second piston positions under an alternating combustion event force in either one of the first or second combustion chambers to compress combustion gases in the other one of the first or second combustion chambers and to move the pump vane between the first and second pump vane positions to drive a working fluid through the pumping chamber. The engine also includes at least one exhaust port disposed in the housing to allow for the exit of combustion gases.
In another embodiment, the combustion event is caused by compression ignition of fuel gases disposed within the combustion chamber. In one preferred embodiment, the engine also includes at least two pairs of pistons arrange to define at least four combustion chamber portions, and at least two pairs of pump vanes arranged to define at least four pumping chamber portions. In another preferred embodiment, each pair of pistons are attached to one pair of pump vanes to form combined piston and pump vane pairs. The combined pairs are collinear and transverse to an axis of common rotation and are rotatable with respect to the axis of common rotation. In this embodiment, the at least four combustion chamber portions and pumping chamber portions are disposed around the axis of common rotation between adjacent pistons and pump vanes respectively.
In yet another preferred embodiment, the engine includes one exhaust port per combustion chamber portion and one combustion chamber intake port per combustion chamber portion, wherein the exhaust ports are equally spaced about the combustion, each intake port is equally spaced about the combustion chamber, and the exhaust and intake ports are equally spaced from one another. In still yet another preferred embodiment, each intake port includes a valve, and at least one of the combined pairs is connected to a sequencing shaft. In this embodiment, the sequencing shaft and the valves are operatively connected so as to synchronize the rotation of the pistons and the opening and closing of the intake valves.
The present invention is further directed to an engine for producing direct hydraulic work having a housing having at least one combustion chamber disposed with the housing, at least one piston disposed within the combustion chamber and dividing the combustion chamber into at least a first combustion chamber portion and a second combustion chamber portion, the piston moveable between a first piston position and a second piston position, at least one fuel intake port disposed in the housing to allow passage of fuel into the first and second combustion chamber portions, a pumping chamber disposed within the housing, and at least one pump vane disposed within the pumping chamber and dividing the pumping chamber into at least a first pumping chamber portion and a second pumping chamber portion, the pump vane coupled to the piston so as to be moveable therewith between a first pump position and a second pump position corresponding to the first and second piston positions respectively. The piston is dimensioned and configured so as to reciprocate between the first and second piston positions under an alternating combustion event force in either one of the first or second combustion chambers to compress combustion gases in the other one of the first or second combustion chambers and to move the pump vane between the first and second pump vane positions to drive a working fluid through the pumping chamber. The engine also includes at least one exhaust port disposed in the housing to allow for the exit of combustion gases and a starter mechanism coupled to the at least one piston and capable of moving the piston between the first and second pistons positions so as to initiate a self-sustaining engine cycle.